Originally posted by voyager6
For me and most Daytonians, the Columbus digitals are harder to get than Cincinnati because the terrain between Dayton and Cincinnati is flatter and they have taller transmitting antennas in Cincy than Columbus.
Actually, Terrain between Dayton + Cincy is generally Hillier than between Dayton and Columbus -- But, None of the "hills" between Dayton and Cincy are as high as the seemingly Flat ground between Columbus and Dayton, such as the ~1200 FT rise. There are some "high spots"(not quite 1200FT) in the Kettering/South Dayton area which I had thought might be an issue for Your location however ....
Also, The Transmitting antenna heights of Columbus and Cincy stations are very much the same, with the exception of some LP analogs, and WCVN/DT in N KY.
Follows are the antenna heights of Various Cincy/Columbus stations, as currently "configured" ...
Columbus DT stations Transmitting antenna Height Above Sea Level :
WSYX-DT : 1715FT ASL
WCMH-DT: 1660FT ASL
WWHO-DT: 1824FT ASL
WBNS-DT : 1718FT ASL
WOSU 34: 2017FT ASL
WTTE-DT : 1665FT ASL
Cincinnati DT stations transmitting antenna Height Above Sea Level :
WCPO-DT: 1578FT ASL
WCVN-DT: 1099FT ASL (Tower in N KY, Likely out of range for N Dayton)
WXIX-DT: 1660FT ASL
WKRC-DT: 1632FT ASL
WSTR-DT: 1765FT ASL
WCET-DT: 1761FT ASL
WLWT-DT: 1705FT ASL
Originally posted by voyager6
If line of sight on a 1000' antenna is about 60 miles, then 30 miles equals about 300' drop ((1-.707) * height). So the midway rise puts you out of line of sight under even a conservative estimation.
I don't think calculating "RF line of sight" and how much that midway rise would put you "out of" RF line of sight is quite that simple ... You would really need to do something such as a "detailed" longely-rice propagation study which takes terrain into account to get the best idea of reception chances for a specific location ... Either that, or just try it, it seems to be working for your specific circumstance ... Again, I might be wrong as I would agree that it is a fairly "close thing" but, I'd say 1450KHZ has a good shot at getting reception of the Columbus stations given a decent outdoor antenna setup, and, I've certianly seen good reception occur in worse cirucmstances ....
For ONE thing, there is optical line of sight, and there is "RF line of sight", RF line of sight is ALLWAYS farther than Optical line of sight, even on UHF. Although the effect is more prevalent on the longer VHF wavelengths, Even on UHF frequencies(at all times anywhere on surface of earth), Signals on VHF/UHF(again, VHF moreso) will be "bent" beyond "optical" line of sight(curvature of earth, hills) a certian amount, basically, by "properties" of the "air" (Humidity/dewpoint/ etc) ALL the time ...
Depending upon the weather, The effect sometimes becomes much more pronounced in certian areas(such as ours which isn't as arid as say, the desert SW, but we don't generally get a lot of "enhancement" during the dry, winter months) when we receive more distant stations than is usually possible beyond curvature of earth via what we call "tropo scatter/Tropo ducting", but Tropo(short for troposphere) scatter(also called Ground Scatter) is ALLWAYS present to a certian extent, effecting both VHF and UHF frequencies.
This "constant ground scatter" is mostly why I receive WCMH 4 from 78 miles(some 15-20 miles or so beyond what should be "RF Line of sight" by most calulations) given their antenna height) All the time, "generally" Watchable about 70% of the time(again, more pronounced because of the longer VHF wavelength involved) and I get a bit of indication of signal from WSYX-DT Most of the time, and at least audio from WTTE 28 ~90~95% of the time -- All with WORSE terrain conditions than is present at your, or 1450KHZ location .... I also USED to be able to watch WBNS 10 much of the time(It, and "way back" when NBC did NFL WCMH 4/WAVE 3 louisville especially worked nicely for Bengals games -) ... Until WCPO-DT came up in 1998 that is I do still see them occasionally w/ant aimed towards Columbus, but it's usually a real mess ....